Why does the NZ First 'values' bill take aim at anti-alcohol immigrants?

New Zealand First's new bill that would require new migrants and refugees to not campaign against alcohol consumption is prompting confusion.

The Respecting New Zealand Values Bill passed at the New Zealand First party's AGM on Sunday, and would require migrants to sign up to 'New Zealand values' like gender equality, marriage equality and the legality of alcohol consumption.

"I can't think of a group that's caused harm to New Zealand culture by opposing alcohol consumption... They are always a health promotion group.

"Those aren't anti-Kiwi. They are evidence-based approaches to reducing harm."

He said alcohol advertising often uses national identity - think of the Southern Speight's man - to convince New Zealanders drinking is part of their identity. Speight's is owned by Japanese holding company, Lion.

New Zealand First's Clayton Mitchell told Wendyl Nissen on RadioLIVE that New Zealand's values are "largely known as Christian-based, but not necessarily aligned to any religion."

"We don't mind what religious background you have - it's not about the religion," Mr Mitchell said.

"It's the way you behave with your religion, or the way you behave with your upbringing, or the way you behave towards other people - and that's what we have to make sure we abide by.

"It goes on and it's going on under our very noses," he said, though he could not provide a specific example.

The bill doesn't have unanimous support from within NZ First. Tracey Martin said the bill is probably unnecessary.

New Zealand First leader Winston Peters was not available for comment due to travel commitments.